People enjoy eating quality food that is prepared by good restaurants. Nevertheless, sometimes people may not want to go to a restaurant, but instead may prefer to have food delivered to them. To meet this demand, a courier may deliver food prepared by a restaurant to a customer at a delivery location. For example, a service may enable customers to order food items from any of a variety of restaurants, and may arrange for couriers to deliver the food items from the restaurants to the customers. If it is too expensive for the courier to deliver the food from the restaurant to the customer, for example a distant customer, a restaurant with a delivery service establishes a fixed delivery zone and does not deliver to customers located outside of this fixed zone. In some cases, the service charges an incremental delivery fee to cater to the customers outside of the fixed zone. High delivery fees can discourage the customer from using the service and can prevent the merchant from expanding the business beyond the fixed zone.